The present invention relates generally to mobile communications, and more specifically to the testing and optimization of a mobile communications network.
Mobile devices (also referred to as user equipment (UE)) that combine high speed mobile access with Internet Protocol (IP) based services (e.g., downloading data such as a web page or music) often communicate using a Universal Mobile Telecommunications System (UMTS) network. UMTS networks are the third generation of personal mobile communication. UMTS is a standard that integrates wireline and wireless systems to provide a universal communications service so that a user can move from place to place while maintaining access to a complete set of services. UMTS may enable a mobile device to use voice as well as transmit and receive data at high data rates such as 2 Mbps. Further, a UMTS network can use High Speed Downlink Packet Access (HSDPA), which changes data rate and resources according to the RF conditions of the UE.
When deploying a UMTS network, a network provider typically has to meet customer constraints described in a customer acceptance document (e.g., a customer contract warranty). In particular, a customer acceptance document typically specifies key performance indicators (KPIs) that the deployed network has to fulfill and the tests that need to be performed in order to measure those KPIs. The customer requires that the deployed UMTS network is measured against the warranted KPIs that are specified in the customer acceptance document. One KPI that is typically important is the capacity of a cell (and, therefore, the capacity of the UMTS network).
Many of the tests that need to be performed to test the UMTS network often require that the network is under load conditions equal to the warranted capacity. The load should be variable in time and power and the load should be uncorrelated in each cell. A UMTS load is often complex because of the mixture of services that are provided by the network.
As a recently deployed network has few real customers (if any), the remaining number of users needed to reach the warranted capacity has to be generated somehow. A realistic way of generating the warranted capacity is by spreading (typically a large number of) real users or terminals (i.e., mobile devices) around the network in a uniform and uncorrelated manner and let them move freely inside the network.
In most cases, however, such a large number of mobile devices are not available or easily accessible. Further, even if the required number of mobile devices could be obtained to run a test at the warranted capacity, the obtaining of the mobile devices may be very expensive for the network provider. Specifically, the network provider would have to purchase many mobile devices and would additionally have to hire a person to carry each mobile device in the network. This is likely very expensive and uncontrolled. Additionally, this solution may introduce large variances in the network, leading to large periods of measurements required in order to obtain reasonable averages. Furthermore, many test failures may occur, potentially resulting in many test repetitions.
Therefore, there remains a need to more efficiently and cost effectively test a UMTS network.